Philips PCF1171CT Datasheet

INTEGRATED CIRCUITS

DATA SH EET

PCF1171C

4-digit LCD car clock

Product speciﬁcation Supersedes data of September 1993 File under Integrated Circuits, IC16

1997 Apr 16

Philips Semiconductors Product speciﬁcation

4-digit LCD car clock PCF1171C

FEATURES

• Driving standard 31⁄2 or a 4-digit LCD

• Internal voltage regulator for 5 V LCD

• Option for external stabilized voltage supply

• 4.19 MHz oscillator

• Integrated oscillator output capacitor and polarization

resistor

• Operating ambient temperature: −40 to +85 °C

• 40-lead plastic SMD, face down (VSO40).

ORDERING INFORMATION

TYPE

NUMBER

PCF1171CT VSO40 plastic very small outline package; 40 leads; face down PCF1171CU − uncased chip in tray

Notes

1. See Fig.1 and Chapter “Package outline” for pin layout and package details.

2. See Chapter “Chip dimensions and bonding pad locations” for pad layout and package details.

NAME DESCRIPTION VERSION

(2)

GENERAL DESCRIPTION

The PCF1171C is a single chip, 4.19 MHz CMOS car clock circuit indicating hours and minutes. It is designed to drive a 31⁄2 or 4-digit liquid crystal display (LCD).

Two external single-pole, single-throw switches will accomplish all time setting functions. A bonding option allows the selection of 12-hour or 24-hour display mode. The circuit is battery-operated via an internal 5 V voltage regulator or by an external stabilized voltage supply.

PACKAGE

(1)

SOT158-2

−

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Philips Semiconductors Product speciﬁcation

4-digit LCD car clock PCF1171C

PINNING

SYMBOL PIN DESCRIPTION

OSC OUT 1 oscillator output OSC IN 2 oscillator input S1 3 set hour S3 4 ±2 minute correction BP 5 64 Hz backplane driver

(common of LCD) ADEG1 6 segment driver C1 7 segment driver E2 8 segment driver D2 9 segment driver C2 10 segment driver E3 11 segment driver D3 12 segment driver C3 13 segment driver E4 14 segment driver D4 15 segment driver C4 16 segment driver B4 17 segment driver S2 18 set minutes S4 19 internal voltage regulation V

20 negative supply S6 21 selectable correction mode S5 22 12/24-hour mode V

23 positive supply A4 24 segment driver F4 25 segment driver G4 26 segment driver B3 27 segment driver A3 28 segment driver F3 29 segment driver G3 30 segment driver P1, P2 31 colon ﬂashing P3, P4 32 colon static B2 33 segment driver A2 34 segment driver F2 35 segment driver G2 36 segment driver B1 37 segment driver

SYMBOL PIN DESCRIPTION

TR 38 test reset; connect to (VDD) TS 39 test speed-up; connect to (V

) 40 positive supply for test and oscillator

inputs

OSC OUT

OSC IN

S1 S3

ADEG1

E2 D2 C2

E3 D3 C3

E4 D4 C4

1 2 3 4 5 6 7 8 9

PCF1171CT

11 12

15 16 17 18 19 20

MSA981

(V )

P3, P4

P1, P2

2714

A4 V

Fig.1 Pin configuration, PCF1171CT, (VSO40).

)

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Philips Semiconductors Product speciﬁcation

4-digit LCD car clock PCF1171C

TIME

P1 (P3)

P2 (P4)

Fig.2 Segment designation of LCD.

Fig.3 Display mode (24-hour mode shown).

MSA985

MSA984

OPERATIONAL INPUTS

Operational inputs S1, S2 and S3 have an internal pull-up resistor to facilitate use of external single-pole, single-throw switches. A specific debounce circuit is integrated as protection against contact debounce and parasitic voltages.

In the description below, an arrangement as shown in Fig.5 is assumed and S1, S2 and S3 refer to the external switches rather than the corresponding inputs.

Set hours, switch S1

Closure of S1 increments the hours according to the correction mode selected by S6 (see Chapter “Input options”).

1997 Apr 16 4

Set minutes/reset seconds, switch S2

When S2 is closed, the minute setting is corrected according to the correction mode determined by S6 (see Chapter “Input options”).

The seconds counter is reset to zero each time S2 is closed, and begins running each time S2 is opened.

Segment test/reset, switches S1 and S2

If S1 and S2 are closed simultaneously all LCD segments are switched on. When the switches are released, the clock starts at 1 : 00 in the 12-hour mode or 0 : 00 in the 24-hour mode.

Philips Semiconductors Product speciﬁcation

4-digit LCD car clock PCF1171C

Time correction ±2 minutes, switch S3

This switch operates in two ranges:

• Displayed time ≥ 58 minutes 00 seconds

• Displayed time ≤ 1 minute 59 seconds.

When switch S3 is pressed in these ranges, the minutes and seconds are reset to zero. For displayed time ≥ 58 minutes 00 seconds, the hour is also incremented by one.

INPUT OPTIONS

In the description below S4, S5 and S6 refer to the external switches shown in Fig.5 rather than to the corresponding inputs.

In a real application, these inputs will normally be bonded to the appropriate level to give the required function mode.

Internal/external regulation, switch S4

For internal regulation, S4 is closed, the internal voltage regulator is active and the voltage supply for the LCD is regulated to 5 V. For external regulation, S4 is open and the circuit has to be supplied with an externally regulated voltage.

12/24-hour mode, switch S5

For 12-hour display mode, S5 is connected to VDD. For 24-hour display mode, S5 is connected to VSS.

Single/continuous correction mode, switch S6

For single-set correction mode, S6 is connected to V

Each closure of S1 or S2 advances the counter by one. For continuous-set correction mode, S6 is connected to

VSS. Momentary closure of S1 or S2 causes single increments as for single-set correction mode. If S1 or S2 is kept closed for more than 1s, the counter is automatically incremented by 1 for each full second that S1 or S2 is kept closed.

TESTING

In normal operation the test inputs TR (pin 38) and TS (pin 39) have to be connected to V

(pin 23). A test

frequency (64 Hz) is available at BP (pin 5). The test mode is activated by connecting TS to VSS (pin 20). All output frequencies are then increased by a factor of 65536. In this mode the maximum input frequency is 100 kHz (external generator at OSC IN). By connecting TR to V

all counters (seconds, minutes and hours) are stopped. After connecting TR to VDD all counters start from an initial state.

The switches/inputs described above also operate in the test mode.

LIMITING VALUES

In accordance with the Absolute Maximum Rating System (IEC 134).

SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT

supply voltage with respect to VSS with internal

note 1 − 8V

regulation disconnected;

amb

stg

all input voltages VSS− 0.3 VDD+ 0.3 V operating ambient temperature −40 +85 °C storage temperature −55 +125 °C

Note

1. Connecting the supply voltage with reverse polarity, will not harm the circuit, provided the current is limited to 10 mA by the external resistor.

HANDLING

Inputs and outputs are protected against electrostatic discharges in normal handling. However, to be totally safe, it is advisable to take handling precautions appropriate to handling MOS devices. Advice can be found in

“Data Handbook IC16, General, Handling MOS Devices”

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